182 citations
,
December 2007 in “BJCP. British journal of clinical pharmacology/British journal of clinical pharmacology” This study demonstrated that hair follicles significantly expedite the absorption of caffeine through the skin compared to interfollicular pathways.
153 citations
,
October 2012 in “Skin Pharmacology and Physiology” This review discusses the use of caffeine in cosmetics for its fat-reducing, antioxidant, and hair growth properties, but reports no new research findings.
114 citations
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January 2007 in “International Journal of Dermatology” This study found that caffeine can stimulate hair growth in vitro and counteract testosterone-induced growth suppression in hair follicles from male AGA patients.
93 citations
,
January 2007 in “Skin Pharmacology and Physiology” In this study, caffeine applied in a shampoo penetrated hair follicles faster and more effectively than through the skin surface within the first 20 minutes.
82 citations
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May 2009 in “BJCP. British journal of clinical pharmacology/British journal of clinical pharmacology” The study reported that combining the Follicular Closing Technique with the Franz diffusion cell is a valuable method for investigating follicular caffeine penetration in vitro, though kinetics differ from in vivo results.